Artificial muscles based on nematic gels De Gennes, Pierre-Gilles; Hébert, Matthieu; Kant, Rama
Macromolecular symposia.,
February 1997, Letnik:
113, Številka:
1
Journal Article
Recenzirano
Mechano-chemical conversion through the swelling of polymer gels suffers from several limitations, as far as the artificial muscles applications are concerned: mechanical response is too slow and ...strong local stress damages the sample. We propose a different approach to bypass these difficulties: artificial muscles based on nematic gels. When the temperature is lowered below the nematic clearing point, strong uniaxial deformations occur. The estimated shape relaxation time is well within actual muscle contraction times.
Petit point Gennes, Pierre-Gilles de
2004., 2004, 2004-10-22
eBook
In this fascinating book, Nobel Prize winner Pierre-Gilles de Gennes wittily captures the lives of personalities from both the academic and the industrial world in delightful bite-size stories. Most ...of the characters in this collection are like those in Aesop's fables, but in modern-day research settings. The book provides a critical account of aberrations (fortunately rare) of the scientific community. Many lessons can be drawn from the stories. For the young researcher, this book is like a telescope: for seeing other human beings beyond his or her laboratory. For the administrator, this book is like a microscope: for seeing inside the human beings huge and complex structures. However, like Aesop's fables, you would not offer the book as a gift to anyone other than a close and wise friend.Petit Point is not a book to be devoured in a single sitting. It is one to be savored and reflected upon - it shows what the world may be like and what we ourselves may become. It is like a mirror - to be visited from time to time.Contents: LetterMastocVéraLanterneLeducEmmyBretonSmirnoffPluvieuxBéziersKubaVladimirAglaéSubtilChazotAnchorCroesusCaesarGuruDourakineSaplirManfredRobertPolymorphRévizorFestonPhilostrateÉliseSpirosAkbarReadership: General.
This volume is a selection of invaluable papers by P-G de Gennes — 1991 Nobel Prize winner in Physics — which have had a long-lasting impact on our understanding of condensed matter. Important ideas ...on polymers, liquid crystals and interfaces are described. The author has added some afterthoughts to the main papers (explaining their successes or weaknesses), and some current views on each special problem. The text is simple and easy to read.
Some Remarks on Polymer Actuators (Résumé) de Gennes, Pierre-Gilles
Polymers for advanced technologies,
October ‐ December 2002, Letnik:
13, Številka:
10-12
Journal Article
Recenzirano
This paper is a summary of some curent research on soft actuators (such as nematic rubbers) and semi soft actuators (such as nafions).
I consider a vesicle with an open pore of small radius rp, exposed to a DNA solution. The crucial moment is the entry, when a chain end faces the pore and enters it. I discuss qualitatively the ...following three characteristic times: (i) the duration of the entry of one chain end (defining the minimum lifetime of the pore) τ e∼ 10-4 sec, (ii) the transfection time τ t (the time required to be sure that one chain has gone in) τ t∼ hours, and (iii) the sliding time τ S (the time between entry of one end and entry of the other end) ∼ 1 sec. A fortunate feature is that sliding may proceed even if the pore tends to close itself after entry.
How Soft Skin Wrinkles Brochard-Wyart, Françoise; de Gennes, Pierre Gilles
Science (American Association for the Advancement of Science),
04/2003, Letnik:
300, Številka:
5618
Journal Article
Recenzirano
Under tension soft layers wrinkle. The distance between wrinkles is a compromise between bending energies and standard deformation energies. The authors discuss research on how soft skin wrinkles.
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